Article

OBJECTIVES: To classify propulsion patterns over surfaces encountered in the
natural environment during start-up and compare selected biomechanical variables
between pattern types. DESIGN: Case series. SETTING: National Veterans Wheelchair
Games, Minneapolis, MN, 2005. PARTICIPANTS: Manual wheelchair users (N=29).
INTERVENTION: Subjects pushed their wheelchairs from a resting position over
high-pile carpet, over linoleum, and up a ramp with a 5 degrees incline while
propulsion kinematics and kinetics were recorded with a motion capture system and
an instrumented wheel. MAIN OUTCOME MEASURES: Three raters classified the first 3
strokes as 1 of 4 types on each surface: arc, semicircular (SC), single looping
over propulsion (SL), and double looping over propulsion (DL). The Fisher exact
test was used to assess pattern changes between strokes and surface type. A
multiple analysis of variance test was used to compare peak and average resultant
force and moment about the hub, average wheel velocity, stroke frequency, contact
angle, and distance traveled between stroke patterns. RESULTS: SL was the most
common pattern used during start-up propulsion (44.9%), followed by arc (35.9%),
DL (14.1%), and SC (5.1%). Subjects who dropped their hands below the rim during
recovery achieved faster velocities and covered greater distances (.016< or =P<
or =.075) during start-up on linoleum and carpet and applied more force during
start-up on the ramp compared with those who used an arc pattern (P=.066).
CONCLUSIONS: Classifying propulsion patterns is a difficult task that should use
multiple raters. In addition, propulsion patterns change during start-up, with an
arc pattern most prevalent initially. The biomechanical findings in this study
agree with current clinical guidelines that recommend training users to drop the
hand below the pushrim during recovery.

Langue : ANGLAIS